The Roof is the fifth stage of Adventure Mode and takes place on top of the player's house. It consists of a five-by-five sloped side in back and a four-by-five straight side in front with a satellite dish on the zombie side and a chimney on the player's side.
Audio and Video
The original roof music (called as Graze the Roof)
Roof stage soundtrack
Straight shooting plants (Peashooters, Starfruits, etc.) will not be able to hit zombies if planted on the sloping side (although they can fire over the edge when planted on the first and second sloped column), so the player will need to use lobbed-shot plants for this stage (the player can use Fume-shrooms too, but the need of waking them up and their short range may prevent the player from using them much). They also need Flower Pots to place plants on the roof. Because it takes place during the day, sun falls from the sky during this stage, and mushrooms fall asleep. There are no Lawn Mowers, so until Roof Cleaners are purchased from Crazy Dave, the player's last line of defense is, unfortunately, their hindmost plants. This stage also has "ambush zombies", which are actually Zombies (or Conehead Zombies and Buckethead Zombies) that are dropped by Bungee Zombies onto the roof, possibly into the player's defenses, although they can be repulsed by Umbrella Leaves. This is similar to the zombies that surface from the Pool and the zombies that come out of graves. Overall, this is the hardest area of the game to overcome.
The plants added to this level are especially made to fit the roof. For example, due to the slope of the roof, catapults must be used. These include the Cabbage-pult, Kernel-pult, and Melon-pult, which are all lobbed-shot plants. These plants are essential to roof levels, because of the slope of the roof. Flower Pots are also essential for planting on the roof, because plants can't be planted on the roof without them. The other plants added in the roof stage are Coffee Beans, Garlics, Umbrella Leaves, and Marigolds.
It is unknown how Vehicle Zombies get up on the roof. However, they may have been dropped by Bungee Zombies. Vehicle Zombies can also be lifted by the Bungee Zombies. It may be a group of Bungee Zombies (five to six) for each vehicle. Also, Vehicle Zombies can fit in the chimney while still riding their vehicles.
When the level is being represented, the words on the screen will say "[The player's name]'s Roof!" with an exclamation point at the end.
In the Festive mode on the iOS versions, despite the stocking having a brain with it, the zombie eats the player's brain instead.
The brain on the stocking could be a fake one, although it could be that the zombies are too unintelligent to notice the brain.
The music played on the Roof is called "Graze the Roof", a pun on the phrase "raise the roof".
The song also sounds a bit like Grasswalk (the Day theme) when it starts playing.
Fume-shrooms and Gloom-shrooms are the only non-Lobbed-shot Plants that can shoot up the slope of the roof.
During the Roof levels (especially Level 5-10) it is unclear how the roof can support all of the heavy zombies, most notably Gargantuars, Zombonis, and Dr. Zomboss's Zombot despite there already being cracks in the roof.
In the Xbox 360 trailer, it is said that the roof has Spanish tiles.
It appears that the roof has flowers and weeds right after the slant. These flowers and such are not sentient unlike other plants in the series.
Despite the fact that the tiles on the roof aren't living, craters will still be repaired over time.
On the Android and iPad versions of the game, there is a hole on the side of the chimney that the zombies walk through, instead of dropping down it.
This may be because these versions have wider screens, so the player would be able to see the zombie disappearing and reappearing in the chimney.
Some zombies still have their body visible as they eat the player's brains. This would imply that the homeowner is actually sitting inside the chimney, watching the battle.
It is unknown why Cactus cannot grow to reach over the roof's slant, like what it does to attack a Balloon Zombie. This may be because it is programmed to only stretch its body up to shoot Balloon Zombies.
On the iPad version, the clouds in the background are shaped like brains.
This is the only stage where plants are already planted on every single level (Flower Pot).